/*
* Copyright (c) 2007 BUSINESS OBJECTS SOFTWARE LIMITED
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Business Objects nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* RestartableQueryResults.java
* Created: ??
* By: ??
*/
package org.openquark.cal.foreignsupport.module.DataGems;
import java.math.BigDecimal;
import java.util.Date;
import org.openquark.util.database.SqlType;
import org.openquark.util.time.Time;
/**
* This class adds random access support to a forward-only resultset.
* If the rows are accessed out of order, then the resultset will be recreated
* and then will seek to the requested row.
*/
public abstract class RestartableQueryResults implements QueryResult {
/** The current query results. */
private QueryResult currentResults;
/** The row at which the result set is currently positioned. */
private int currentRow = 0;
/**
* Constructor for RestartableQueryResults.
*/
public RestartableQueryResults() {
this(null);
}
/**
* Constructor for RestartableQueryResults.
*/
public RestartableQueryResults(QueryResult currentResults) {
this.currentResults = currentResults;
}
/**
* Create a new resultset, positioned at the start.
*/
protected abstract QueryResult createResultSet() throws DatabaseException;
/**
* Returns the current query results, creating a new one if none exists.
* @return the current query results
*/
private QueryResult getQueryResults() throws DatabaseException {
// Create the initial resultset, if necessary.
if (currentResults == null) {
// System.out.println(">>>Creating resultset.");
currentResults = createResultSet();
currentRow = 0;
}
return currentResults;
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#close()
*/
public void close() throws DatabaseException {
if (currentResults != null) {
currentResults.close();
}
currentResults = null;
currentRow = 0;
}
/**
* Moves to the specified row.
*/
public boolean moveToRow(int row) throws DatabaseException {
// Create the initial resultset, if necessary.
getQueryResults();
// If the requested row is the same as the current one, then no action
// is required.
if (row == currentRow) {
// System.out.println("Returning current row: " + row);
return true;
}
// If the requested row precedes the current position, then recreate the
// resultset and start from the beginning again.
if (row < currentRow) {
// System.out.println(">>>Creating resultset.");
if (currentResults != null) {
currentResults.close();
}
currentResults = createResultSet();
currentRow = 0;
}
// If the requested row is the new one, then advance the resultset
// position.
// System.out.println("On row " + currentRow + " moving to row " + row);
while (row > currentRow) {
boolean moveResult = currentResults.moveNext();
if (!moveResult) {
currentResults.close();
currentResults = null;
currentRow = 0;
return false;
}
++currentRow;
}
return true;
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getColumnCount()
*/
public int getColumnCount() throws DatabaseException {
return getQueryResults().getColumnCount();
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getColumnLabel(int)
*/
public String getColumnLabel(int column) throws DatabaseException {
return getQueryResults().getColumnLabel(column);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getColumnName(int)
*/
public String getColumnName(int column) throws DatabaseException {
return getQueryResults().getColumnName(column);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getColumnIndex(java.lang.String)
*/
public int getColumnIndex(String columnName) throws DatabaseException {
return getQueryResults().getColumnIndex(columnName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getColumnType(int)
*/
public SqlType getColumnType(int column) throws DatabaseException {
return getQueryResults().getColumnType(column);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getColumnDisplaySize(int)
*/
public int getColumnDisplaySize(int column) throws DatabaseException {
return getQueryResults().getColumnDisplaySize(column);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#moveFirst()
*/
public boolean moveFirst() throws DatabaseException {
return moveToRow(1);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#moveNext()
*/
public boolean moveNext() throws DatabaseException {
return moveToRow(currentRow + 1);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#recordAt(int)
*/
public boolean recordAt(int row) {
// Return whether the resultset has been exhausted (the cursor is after the last record)
// If an error occurs, we report the end of the result set (return false)
try {
return moveToRow(row);
} catch (Exception e) {
// An error occured, report no more records
return false;
}
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#wasLastFetchNull()
*/
public boolean wasLastFetchNull() throws DatabaseException {
return getQueryResults().wasLastFetchNull();
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#resultGetRecord(int)
*/
public RecordPlaceholder resultGetRecord(int row) throws DatabaseException {
return new RecordPlaceholder(this, row);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowString(int)
*/
public String getCurrentRowString(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowString(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowString(java.lang.String)
*/
public String getCurrentRowString(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowString(colName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowInt(int)
*/
public int getCurrentRowInt(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowInt(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowInt(java.lang.String)
*/
public int getCurrentRowInt(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowInt(colName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowLong(int)
*/
public long getCurrentRowLong(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowLong(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowLong(java.lang.String)
*/
public long getCurrentRowLong(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowLong(colName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowDouble(int)
*/
public double getCurrentRowDouble(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowDouble(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowDouble(java.lang.String)
*/
public double getCurrentRowDouble(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowDouble(colName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowDecimal(int)
*/
public BigDecimal getCurrentRowDecimal(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowDecimal(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowDecimal(java.lang.String)
*/
public BigDecimal getCurrentRowDecimal(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowDecimal(colName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowDate(int)
*/
public Date getCurrentRowDate(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowDate(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowDate(java.lang.String)
*/
public Date getCurrentRowDate(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowDate(colName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowTime(int)
*/
public Time getCurrentRowTime(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowTime(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowTime(java.lang.String)
*/
public Time getCurrentRowTime(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowTime(colName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowBoolean(int)
*/
public boolean getCurrentRowBoolean(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowBoolean(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowBoolean(java.lang.String)
*/
public boolean getCurrentRowBoolean(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowBoolean(colName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowBytes(int)
*/
public byte[] getCurrentRowBytes(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowBytes(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowBytes(java.lang.String)
*/
public byte[] getCurrentRowBytes(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowBytes(colName);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowObject(int)
*/
public Object getCurrentRowObject(int colIndex) throws DatabaseException {
return getQueryResults().getCurrentRowObject(colIndex);
}
/**
* @see org.openquark.cal.foreignsupport.module.DataGems.QueryResult#getCurrentRowObject(java.lang.String)
*/
public Object getCurrentRowObject(String colName) throws DatabaseException {
return getQueryResults().getCurrentRowObject(colName);
}
}